U.S. Pat. No. 4,835,809 to Roumagnac, incorporated herein in its entirety by this reference, discloses various embodiments of an automatic device for cleaning swimming pools. The device includes a brush attached either to the lower edge or the bottom of its body to contact surfaces of the swimming pool and displace debris positioned there. According to the Roumagnac patent, the brush may be arched and of "substantially the same shape and length of the lower edge" of the body, for example, or "in the form of a circular cordon attached to the periphery of the bottom." Also included in the body of the device is an aspiration orifice, which may be annular, as shown in FIG. 5 of the Roumagnac patent, or "in the form of a narrow arched window" of FIG. 3.